Smelting process.



E. DEDOLPH.

SMELTING mocnss.

Patented May 31, 1910.

a Z I .Q |4 W $x AA w N m APPLIOATION FILED NOV. 4, 1909.

W/TNESSES:

EDUARD DEDOLPH, or KASLO, BRITISH cou'ninam, CANADA.

SIVIIELTING- rnocnss;

Specification of Letters Patent.

'Patented Ma 31, 1910.

Application filed November 4, 1909. Serial No. 526,168.

To all whom it may concern:

Be it known that I, EDUARD DEDOLPH, a subject of the King of Great Britain, residing at Kaslo, in the county of West Kootenay, Province of British Columbia,

Canada, have invented new and useful Improvements in Smelting Processes, of which the following is a specification.

The invention relates to the smelting of lead ores, zincy lead, leady zinc, and zinc ores, and zincy slag.

' downward toward the front.

The invention consists in the continuous process of smelting such ore and slag, recovering the metal as oxid in the form of fume, as described and claimed hereinafter.

In the accompanying drawing is shown in vertical longitudinal section a furnace for carrying my invention into effect.

The ore is first crushed to from about 4 to 6 mesh, and then mixed with carbonaceous fuel for reducing the metals. Suitable fluxes are mixed with the charge when there is enough silver or gold in the ore, so that the resulting slag can easily be smelted in a blast furnace to recover these metals; and, in general, such proper fluxes may be added as may be required by good metallurgical practice. Coke, coke breeze, slackcoal, or any other fuel may be used. The material is then charged direct in the furnace, the body of which is preferably an elongated, substantially horizontal drum 1, lined inside with refractory material, like magnesia brick, fire-brick, etc. This drum is adapted to be revolved slowly by any suitable means,

as through gearing 2, 3, being supported by rollers 15; and tapers somewhat from front to rear, so that the bottom always slopes The material is admitted through a hopper and chute 4, 5, at the rear of the furnace, and travels gradually along the bottom of the revolving drum to the front thereof, where the slag escapes through a slag spout 6. Preferably, the drum is provided at the front with a ledge or curb 7, which preserves a suitable depth of material on the bottom of the drum, to be impinged by the flame from the burners 8 and air from the twyers 9. An annular slag spout or lip 16 may be bolted to the ledge 7, and may be renewed from time to time. A ledge or curb 17 may be provided at the rear of the drum, also. Both burners and twyers are inclined downward through the front of the furnace, the twyers above the burners. Preferably, the

front of the furnace is in the nature of a water-jacket 10.

The metal is oxidized and the fumes pass in part out of the front of the drum through a flue 11, and in part under a stationary wall 12 at the rear end of the drum, and up a flue 13. The opening to this latter flue is behind the material as it rests upon the bottom of the drum after first being ad mitted to the furnace, and the draft from the front of the furnace through this fine serves to preheat the material. A damper 14 controls the opening to the flue 13, and affords means for regulating the draft. The fines 11 and 13 may and preferably do dcliver to a common flue, which delivers to suitable collecting apparatus. When the damper 14 is fully open, the entire draft or a large part thereof passes out into flue 13; but as the damper is closed, more and more of the draft is caused to pass into the flue 11.

With this process and apparatus, there is but one operation, in place of the two successive operations of roasting and smelting, the recovery is good, and it is possible to treat low-grade ores which otherwise could not be handled at all.

l/Vith an ore charge of oxid or carbonate of zinc and lead, or zinc or lead, the hot carbon 0f the fuel mixed with the charge reduces the oXid or carbonate to metal; then the air strikes this metal and oxidizes it again, carrying it away as fume. If the ore charge is sulfid, the result is the same, though the action is more complicated. It is gradually roasted as it proceeds along the bottom of the drum, being continuously turned and exposed to heat and air. It is not roasted altogether dead, but some of the lead and zinc is volatilized as sulfate and a small amount of sulfid. As the charge advances farther toward the front of the drum and the heat increases, the ore is believed to be reduced to metal, and this metal then oxidized and carried away as fume.

Two drums can advantageously be employed in conjunction, each connected with a separate baghouse, and preferably arranged one behind the other. The charge is supplied to the. first revolving drum, and

air and heatare applied to bring the temperature to about 1300 Celsius, whereby most of the zinc is driven ofi, to be collected in its bagliouse. In this way a fairly clean separation of the lead from the zinc 1s effected, which is of great value if it is desired to re-smelt the lead with theresidue (slag), containin gold and silver.

It may be note that the flare of the drum forward results in the ore being spread farther apart as it advances. By arranging the twyers above the burners a hot fire is insured.

Having thus described my invention and in what manner the same is to be performed, what I claim as new is:

1. The continuous process of extracting lead or zinc or both from their ores or slag as oxid in the form of fume, which consists in continuously supplying the material, mixed with fuel, to an inclosed chamber, causing the material to travel slowly along the bottom of said chamber, admitting flame and air to the chamber, the flame being admitted at a region remote from the region where the material is admitted to the chamber, continuously liberating the metal as oxid in the form of fume and carrying off and collecting the fume thus formed, and continuously removing the residue from the chamber.

2. The process of extracting lead or zinc or both from their ores or slag as oxid in the form of fume, which consists in supplying the material mixed with carbonaceous fuel, to an inclosed chamber, causing the material to travel slowly along the bottom of said chamber, directing flame and air toward the material remote from the region where the material is admitted to the chamber, causin the hot draft to travel over the material 1n the direction reverse to the travel of the material liberating the metal as oxid in the form of fume, and carrying ofi and collecting the fume thus formed.

3. The process of extracting lead or zinc or both from their ores or slag as oxid in the form of fume, which consists in supplying the material mixed with fuel, to one end of a revolving drum, causing the material to travel along the bottom of the drum, admitting flame and air at the other end of the drum and causing the hot draft to travel over the material in the direction reverse to the travel of the material, thus liberatin the metal as oxid in the form of fume, an carrying off and collecting the fume thus formed.

4:. The process of smelting ore or slag containin both lead and zinc, effecting separation o the metals, which consists in supplying the material mixed with fuel to a chamber, causing the material to travel slowly along the bottom of the chamber, heating the material as it travels with access of air to form an oxidizing atmosphere, thus oxidizing the lead and carryin it ofi in the form of fume, mixing the resi ue with more fuel and supplying it to a second chamber, causin it to travel slowly along the bottom thereof, heating the residue as it travels with access of air to form an oxidizing atmosphere, the residue being heated to a higher temperature than the ori inal mixture, thus oxidizing the zinc and carrying it off in the form of fume.

5. The continuous process of smelting lead ores, zincy lead ores, leady zinc ores, lead ores and slag, recovering the metal in the form of fume, which consists in continuously charging the material, mixed with fuel, to a rotating drum along the bottom of which the material is caused to travel, heating the material as it travels with access of air to form an oxidizing atmosphere, thus continuously as the material travels, reducing the metal, then oxidizing it, and carrying off and collecting the fume thus formed.

6. The continuous process of smelting lead ores, zincy lead ores, leady zinc ores and zinc ores, recovering the metal in the form of fume, which consists in continuously charging the ore, crushed and mixed with fuel, to a rotating drum along the bottom of which the material is caused to travel, heating the material as it travels with access of air to form an oxidizing atmosphere, thus continuously and successively as the material travels, roasting the ore, reducing to metal, oxidizing the metal, and 100 carrying off and collecting the fume thus formed.

7. The continuous process of extracting lead or zinc or both from their ores and slag as oxid in the form of fume, which consists in crushing the ore or slag and mixin the material with fuel, continuously supp ying the mixture to an inclosed chamber, causing the material to travel slowly along the bottom of said chamber, directing flame and air downward upon the traveling material, producing an oxidizing atmosphere, the region of flame impingement being remote from the region where the material is admitted to the chamber, whereby the material is progressively heated as it travels, continuously liberating the metal as oxid in the form of fume and carrying 0E and collecting the fume thus formed, and continuously removing the residue from the 12( chamber.

EDUARD DEDOLPH.

Witnesses:

W. F. CooHRANE, LESLIE CRAWFORD. 

